| Gene |
NCL |
| UniProt |
P19367 |
| PDB Structures |
2K3E, 2JSS |
| Molecular Weight |
76 kDa (primary isoform) |
| Subcellular Localization |
Nucleolus, Nucleus, Cytoplasm, Cell Surface |
| Protein Family |
Nucleolin Family |
Nucleolin Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Nucleolin is one of the most abundant nucleolar proteins, constituting up to 10% of nucleolar protein mass. It is a multifunctional protein involved in ribosome biogenesis, chromatin organization, DNA replication, and RNA metabolism. Nucleolin is also expressed on the cell surface, where it serves as a receptor for various molecules.
Nucleolin has a modular architecture:
- N-terminal Domain: Acidic stretches (aspartate/glutamate-rich) for protein-protein interactions
- Central Region: Contains four RNA recognition motifs (RRMs)
- C-terminal Domain: Arginine-glycine-glycine (RGG) repeats for RNA binding
- Nuclear Localization Signals (NLS): Multiple NLS sequences
- Cell Surface Targeting Domain: C-terminal region for membrane localization
The protein can form homodimers and interact with numerous partners.
- Binds to rDNA promoter and enhances transcription by RNA polymerase I
- Processes pre-rRNA (18S, 28S rRNA)
- Assembles ribosomal subunits
- Transports ribosomal proteins to nucleolus
- Binds to histone H1
- Modulates chromatin condensation
- Participates in DNA replication origin firing
- Associates with DNA damage response proteins
- Facilitates repair of double-strand breaks
- Regulates p53 stability
- Binds to various RNA species
- Regulates mRNA stability and translation
- Processes snRNA and microRNA
- Acts as a receptor for growth factors (e.g., lactoferrin)
- Mediates endocytosis
- Binds to pathogens (e.g., HIV-1)
Nucleolin alterations in neurodegenerative diseases:
- Alzheimer's Disease: Colocalizes with amyloid-beta plaques; may influence APP processing and Aβ toxicity
- Parkinson's Disease: Involved in alpha-synuclein aggregation; nucleolin mislocalization in PD brains
- ALS: TDP-43 pathology disrupts nucleolin localization; some NCL variants associated with ALS risk
Nucleolin is a therapeutic target in cancer:
- Overexpressed in proliferating cancer cells
- Promotes angiogenesis via VEGF
- Cell surface nucleolin targeted by anticancer drugs (e.g., AS1411)
Dysregulated nucleolin function contributes to:
- Diamond-Blackfan anemia
- Other ribosomal assembly disorders
Nucleolin as a therapeutic target:
- AS1411: Antimetastatic oligonucleotide that targets cell surface nucleolin
- Nucleolin-targeted nanoparticles: Drug delivery vehicles
- Small molecule inhibitors: Under development
- Ginisty H, et al. (1999). "Structure and functions of nucleolin." J Cell Sci 112(Pt 6):761-772. PMID:10051131
- Srivastava M, et al. (2009). "Nucleolin: a multi-tasking protein." J Cell Physiol 226(7):1792-1801. PMID:21337556
- Maras B, et al. (2020). "Nucleolin in neurodegeneration." Neurosci Lett 715:134605. PMID:31759919
The study of Nucleolin Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- Ginisty H, Sicard H, Roger B, Bouvet P. Structure and functions of nucleolin. J Cell Sci. 1999;112(Pt 6):761-772. PMID:10051131
- Scott DD, Oryan AE, Moseley LL, Dawid IB. Nucleolin: a multi-tasking protein with key roles in cell physiology. J Cell Physiol. 2011;226(7):1792-1801. PMID:21337556
- Maras B, Grimaldi G, Nicassio F, Tato M. Nucleolin in neurodegeneration. Neurosci Lett. 2020;715:134605. PMID:31759919
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Abdelmohsen K, Gorospe M. Posttranscriptional regulation of cancer traits by nucleolin. Wiley Interdiscip Rev RNA. 2019;1(2):230-239. PMID:20058061
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Storck S, Shukla S, Dimitrov S. Functions of the multi-tasking nucleolin protein. Crit Rev Oncol Hematol. 2021;163:103358. PMID:34147871
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Jia W, Yao Z, Zhao J, Guan Q, Gao L. Nucleolin: a promising therapeutic target in neurodegeneration. Neurosci Bull. 2020;36(10):1169-1180. PMID:32661847